Added APT_OLE_JSRat rule

Added APT_OLE_JSRat rule. URL:
https://blogs.mcafee.com/mcafee-labs/stealthy-cyberespionage-campaign-attacks-with-social-engineering

malware/APT_OLE_JSRat.yar

+/*
+    This Yara ruleset is under the GNU-GPLv2 license (http://www.gnu.org/licenses/gpl-2.0.html) and open to any user or organization, as    long as you use it under this license.
+
+*/
+
+rule APT_OLE_JSRat
+{
+meta:
+	author = "Rahul Mohandas"
+	Date = "2015-06-16"
+	Description = "Targeted attack using Excel/word documents"
+strings:
+	$header = {D0 CF 11 E0 A1 B1 1A E1}
+	$key1 = "AAAAAAAAAA"
+	$key2 = "Base64Str" nocase
+	$key3 = "DeleteFile" nocase
+	$key4 = "Scripting.FileSystemObject" nocase
+condition:
+	$header at 0 and (all of ($key*) )
+}
\ No newline at end of file